Room temperature neutron diffraction, optical and magnetic properties of Co(Cr1-xMnx)2O4 (x =0.0 and 0.30)

We report here the effect of 30% Mn substitution on structure and magnetic properties of multiferroic CoCr2O4. Room temperature neutron diffraction studies were carried out on polycrystalline Co(Cr1-xMnx)2O4 (x=0.00 and 0.30) samples to determine structural properties. It has been observed that 30% Mn substitution for Cr in CoCr2O4 leads to increase in the ferrimagnetic transition temperature, (Tc) from ∼96 K to ∼114 K along with the magneto-structural transition temperature, (Ts) from ∼26 K to ∼32 K. In addition, optical properties were studied by UV-visible technique in the range of 200-800 nm. The energy band gap is found to decrease in compare to parent compound. Both magnetization and band gap variation can be explained using the spin-exchange interactions present in these systems.